docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          # extract dictionaries of coefficients specific to required
          # intensity measure type
          C = self.COEFFS[imt]
  
          mean = self._compute_mean(C, rup, dists, sites, imt)
  
          stddevs = self._get_stddevs(C, stddev_types, sites.vs30.shape[0])
  
          return mean, stddevs